private DrawingCanvas canvas = new DrawingCanvas(); private JButton colorButton; // the button for colour, so we can change its background to the current color.
private JTextField textField; // the field for entering text to put on the canvas // fields for recording the information needed to perform the next action
private enum Action {Line,Rect, Oval, Triangle, Text, Dot, Move, Delete, Push, Pull}; private int pressedX; //where the mouse was pressed
private int pressedY; //where the mouse was pressed
private Action currentAction = Action.Line;
private Color currentColor = Color.black; private List<Shape> shapes = new ArrayList <Shape>();
/** Constructor sets up the GUI. */
public MiniDraw(){
frame.setSize(800,600); //The graphics area
canvas.addMouseListener(this);
frame.getContentPane().add(canvas, BorderLayout.CENTER); //The buttons
JPanel topPanel = new JPanel( );
frame.getContentPane().add(topPanel, BorderLayout.NORTH);
JPanel botPanel = new JPanel( );
frame.getContentPane().add(botPanel, BorderLayout.SOUTH);
addButton(topPanel, "New");
addButton(topPanel, "Open");
addButton(topPanel, "Save");
addButton(topPanel, "Delete");
addButton(topPanel, "Move");
colorButton = addButton(topPanel, "Color"); // remember the button so we can change its colour
addButton(topPanel, "Push");
addButton(topPanel, "Pull");
addButton(topPanel, "Reverse");
addButton(topPanel, "Quit"); botPanel.add(new JLabel("Shapes: "));
addButton(botPanel, "Line");
addButton(botPanel, "Rect");
addButton(botPanel, "Oval");
addButton(botPanel, "Triangle");
addButton(botPanel, "Dot");
addButton(botPanel, "Text");
textField = new JTextField("Enter text", 12);
botPanel.add(new JLabel(" : "));
botPanel.add(textField); frame.setVisible(true);
} /** Utility method to make new button and add it to the panel
Returns the button, in case we need it. */
private JButton addButton(JPanel panel, String name){
JButton button = new JButton(name);
button.addActionListener(this);
panel.add(button);
return button;
} /** Respond to button presses */ public void actionPerformed(ActionEvent e){
String button = e.getActionCommand();
//System.out.printf("Button: %s\n", button); //for debugging
if (button.equals("New") )
newDrawing();
else if (button.equals("Open") )
openDrawing();
else if (button.equals("Save") )
saveDrawing();
else if (button.equals("Color") )
selectColor();
else if (button.equals("Reverse") )
reverseDrawing();
else if (button.equals("Quit") )
frame.dispose();
else{ //
currentAction = Action.valueOf(button); // converts the String to an Action.
}
} /** Sets the current color.
* Also changes the color of the Color button and sets the background color of the canvas */
private void selectColor(){
Color newColor = JColorChooser.showDialog(frame,"Choose Color for new shapes", currentColor);
if (newColor!=null){
currentColor=newColor;
colorButton.setBackground(currentColor);
}
} // Respond to mouse events
/** When mouse is pressed, remember the position in order to construct the Shape when
* the mouse is released. */
public void mousePressed(MouseEvent e) {
int x = e.getX(); int y = e.getY();
//System.out.printf("Pressed at (%d, %d)\n", x, y); //for debugging
pressedX = x;
pressedY = y;
} /** When the Mouse is released, depending on the currentAction,
* either construct the shape that was being drawn, or perform the
* action (delete or move) on the shape under the point where the mouse was pressed.*/
public void mouseReleased(MouseEvent e) {
int x = e.getX(); int y = e.getY();
//System.out.printf("Released at (%d, %d)\n", x, y); //for debugging
if (currentAction==Action.Move)
moveShape(pressedX, pressedY, x, y);
else if (currentAction==Action.Delete)
deleteShape(x, y);
else if (currentAction==Action.Push)
pushShapeBackward(x, y);
else if (currentAction==Action.Pull)
pullShapeForward(x, y);
else
addShape(pressedX, pressedY, x, y);
} public void mouseClicked(MouseEvent e) {} //needed to satisfy interface
public void mouseEntered(MouseEvent e) {} //needed to satisfy interface
public void mouseExited(MouseEvent e) {} //needed to satisfy interface
// Helper methods for implementing the button and mouse actions
/** Start a new drawing. */
public void newDrawing(){
shapes = new ArrayList<Shape>();
canvas.clear();
}
/** Open a file, and read all the shape descriptions into the current drawing. */
public void openDrawing(){
String fname = FileChooser.open();
if (fname==null) return;
try {
Scanner file = new Scanner(new File(fname));
//System.out.printf("Opening file %s\n", fname);
shapes = new ArrayList<Shape>();
while (file.hasNext()){
String shapetype = file.next().toLowerCase();
if (shapetype.equals("oval"))
shapes.add(new Oval(file));
else if (shapetype.equals("rectangle"))
shapes.add(new Rectangle(file));
if (shapetype.equals("line"))
shapes.add(new Line(file));
if (shapetype.equals("textshape"))
shapes.add(new TextShape(file));
else if (shapetype.equals("triangle"))
shapes.add(new Triangle(file));
else if (shapetype.equals("dot"))
shapes.add(new Dot(file));
}
render();
}
catch(IOException e) {
System.out.println(e.getMessage());
e.printStackTrace();
}
} /** Save the current drawing to a file. */
public void saveDrawing(){
String fname =FileChooser.save();
if ( fname == null )
return;
try{
PrintStream f = new PrintStream( new File( fname ));
for ( Shape shape : shapes )
f.println( shape.toString());
f.close ();
}
catch(IOException ex){
System.out.println(ex.getMessage());
ex.printStackTrace();
}
}
/** Returns the shape under the position (x y), or null if no such shape */
public Shape findShape(int x, int y){
for (int i = shapes.size()-1; i>=0; i--){ // must go backwards, so can't use foreach
Shape shape = shapes.get(i);
if (shape.pointOnShape(x, y))
return shape;
}
return null; // no shape found at position
}
/** Moves the shape that was under the mousePressed position (pressedX, pressedY)
to where the mouse was released.
Ie, move it by (newX-pressedX) and (newY-pressedY)
*/
public void moveShape(int fromX, int fromY, int toX, int toY){
//System.out.printf("Moving shape under (%d, %d) to (%d, %d)\n", pressedX, pressedY, newX, newY); //for debugging
Shape shape = findShape(fromX, fromY);
if (shape!= null)
shape.moveBy((toX-fromX), (toY-fromY));
render();
} /** Deletes the shape that was under the mouseReleased position (x, y)
*/
public void deleteShape(int x, int y){ for ( Shape shape : shapes) {
if ( shape.pointOnShape(x, y ))
shapes.remove ( shape );
}
render();
}
/** Pull the shape under the mouse one position closer to the "front"
of the drawing */
public void pullShapeForward(int x, int y){
// System.out.printf("Pulling shape under (%d, %d) forward\n", x, y); //for debugging
// YOUR CODE HERE
Shape shape = findShape( x, y );
if (shape!=null ) {
int index = shapes.indexOf(shape);
if ( index< shapes.size()-1){
shapes.remove(index);
shapes.add( index+1,shape);
}
render();
}
}
/** Push the shape under the mouse one position further from the "front"
of the drawing */
public void pushShapeBackward(int x, int y){
//System.out.printf("Pushing shape under (%d, %d) backward\n", x, y); //for debugging
// YOUR CODE HERE
Shape shape = findShape(x, y );
if ( shape!=null ){
int index = shapes.indexOf(shape);
if( index > 0 )
shapes.remove( index);
shapes.add( index-1, shape);
}
render();
}
/** Reverse the order of the shapes in the drawing */
public void reverseDrawing(){ List<Shape>temp = new ArrayList<Shape>();
while ( shapes.size() > 0 ) {
temp.add ( shapes.remove(shapes.size()-1));
}
shapes= temp;
render();
}
/** Construct a new Shape object of the appropriate kind (depending on currentAction)
Uses the appropriate constructor of the Line, Rectangle, Oval, TextShape, or Triangle classes.
adds the shape it to the collection of shapes in the drawing, and
renders the shape on the canvas */
public void addShape(int x1, int y1, int x2, int y2){
//System.out.printf("Drawing shape %s, at (%d, %d)-(%d, %d)\n", currentAction, pressedX, pressedY, x, y); //for debugging
Shape shape = null;
if (currentAction==Action.Line)
shapes.add(new Line(x1, y1, x2, y2, currentColor));
if (currentAction==Action.Triangle)
shapes.add(new Triangle(x1, y1, x2, y2, currentColor));
if (currentAction==Action.Dot)
shapes.add(new Dot(x2, y2, currentColor));
else if (currentAction==Action.Text)
shapes.add(new TextShape(x2, y2, textField.getText(), currentColor));
else{
int left= Math.min(x1, x2);
int top= Math.min(y1, y2);
int width= Math.abs(x1 - x2);
int height= Math.abs(y1 - y2);
if (currentAction==Action.Rect)
shapes.add(new Rectangle(left, top, width, height, currentColor));
else if (currentAction==Action.Oval)
shapes.add(new Oval(left, top, width, height, currentColor));
}
render();
} public void render(){
canvas.clear(false);
for (Shape shape : shapes){
shape.render(canvas);
}
canvas.display();
} public static void main(String args[]){
new MiniDraw();
}}